Acute Vestibular Syndrome (Vestibular Neuronitis)
AVS is a type of spinning vertigo that comes on suddenly, without warning, and lasts at least 24 hours or more. People usually have severe nausea and vomiting and find it difficult to walk. Recovery takes weeks to months in most cases.
The two most common causes of AVS are inner ear infection and stroke. Inner ear infection is most likely from a virus that lives in the nerve and then becomes active spontaneously, such as the HSV family. Stroke is more typically seen in patients who have risk factors for stroke such as high blood pressure, high cholesterol, diabetes, family history of stroke, obstructive sleep apnea, atrial fibrillation, and smoking. Neither infection nor stroke can be definitively identified using MRI or CT.
Treatment is supportive. Some patients do well with steroids given within the first 3 days of symptoms. All patients benefit from physical (vestibular) therapy to improve balance and help the brain accomodate to the change in equilibrium.